The newly made LED light strip is always very bright, but why is it getting darker after a period of use? What's the reason?

LED light source has a very hidden parameter, called "light decay"?

Light decay refers to the phenomenon that the light intensity of the light source will gradually decrease after a period of use, and can not be restored. The value of the decrease is also called LED light decay.

Light decay generally refers to its luminous flux. When charging the surface of the photosensitive drum, with the accumulation of the charge on the surface of the photosensitive drum, the potential increases continuously, and finally reaches the "saturation" potential, which is the highest potential. The surface potential will decrease with the passage of time. Generally, the working potential is lower than this potential. The process that the potential naturally decreases with time is called "dark decay" process. When the photosensitive drum is scanned and exposed, the potential of the dark area (the surface of the photoconductor that is not illuminated by light) is still in the process of dark decay; In the bright region (the surface of the photoconductor irradiated by light), the carrier density in the photoconductive layer increases rapidly, the conductivity increases rapidly, and the photoconductive voltage is formed, the charge disappears rapidly, and the surface potential of the photoconductor also decreases rapidly. It's called "light decline" and slows down in the end.

In general, the manufacturers of LED lamp packaging do the test in the laboratory conditions (25 ℃ room temperature), with 20mA DC continuous lighting led1000 hours to compare the light intensity before and after lighting.

Light attenuation calculation method:

N-hour decay = 1 - (N-hour flux / 0-hour flux)

The above are the reasons for light failure. As the most widely used lighting decoration product, LED light band has a very chaotic market price. When many consumers get the light band, they think the product is very bright and OK, and then there is a large light failure or dead light phenomenon.

The reason is that in order to pursue the low price, some consumers purchase inferior lamp belts. They can't see the quality in a short time. After lighting for a long time, they find the problem. Unqualified heat dissipation circuit board and non original silicone fluorescent glue are used for the purchased lamp belt. In order to pursue brightness, some manufacturers use out of range current to light the lamp, which causes the lamp bead to heat rapidly, and then causes serious light decay, leading to the complete death of the lamp.

I hope you can choose a regular factory with quality assurance when purchasing light belt